Orthogonal R/G/B Upconversion Luminescence-based Full-Color\nTunable Upconversion Nanophosphors for Transparent Displays

Abstract

Here,\nexcitation orthogonalized red/green/blue upconversion luminescence\n(UCL)-based full-color tunable rare-earth (RE) ion-doped upconversion\nnanophosphors (UCNPs) are reported. The LiREF₄-based core/sextuple-shell\n(C/6S) UCNPs are synthesized, and they consist of a blue-emitting\ncore, green-emitting inner shell, and red-emitting outer shell, with\ninert intermediate and outermost shells. The synthesized C/6S UCNPs\nemit blue, green, and red light under 980, 800, and 1532 nm, respectively.\nImportantly, by combining incident near-infrared (NIR) light with\nvarious wavelengths (800, 980, and 1532 nm), full-color UCL including\nblue, cyan, green, yellow, orange, red, purple, and white UCL is achieved\nfrom the single C/6S UCNP composition. The color gamut obtained from\nthe C/6S UCNPs shows 101.6% of the sRGB standard color gamut. Furthermore,\ntransparent C/6S UCNP-polydimethylsiloxane (PDMS) composite is prepared.\nFull-color display realized in the transparent C/6S UCNP-PDMS composite\nindicates the feasibility of constructing the C/6S UCNP-based three-dimensional\nvolumetric displays with wide color gamut.